As used herein, the term “user equipment” (alternatively “UE”) might in some cases refer to mobile devices such as mobile telephones, personal digital assistants, handheld or laptop computers, and similar devices that have telecommunications capabilities. Such a UE might include a device and its associated removable memory module, such as but not limited to a Universal Integrated Circuit Card (UICC) that includes a Subscriber Identity Module (SIM) application, a Universal Subscriber Identity Module (USIM) application, or a Removable User Identity Module (R-UIM) application. Alternatively, such a UE might include the device itself without such a module. In other cases, the term “UE” might refer to devices that have similar capabilities but that are not transportable, such as desktop computers, set-top boxes, or network appliances. The term “UE” can also refer to any component that can terminate a communication session for a user. Also, the terms “user equipment,” “UE,” “user agent,” “UA,” “user device,” and “mobile device” might be used synonymously herein.
As telecommunications technology has evolved, more advanced network access equipment has been introduced that can provide services that were not possible previously. This network access equipment might include systems and devices that are improvements of the equivalent equipment in a traditional wireless telecommunications system. Such advanced or next generation equipment may be included in evolving wireless communications standards, such as Long-Term Evolution (LTE) and LTE-Advanced (LTE-A). For example, an LTE or LTE-A system might be an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and include an E-UTRAN node B (or eNB), a wireless access point, or a similar component rather than a traditional base station. As used herein, the term “access node” refers to any component of the wireless network, such as a traditional base station, a wireless access point, or an LTE or LTE-A node B or eNB, that creates a geographical area of reception and transmission coverage allowing a UE or a relay node to access other components in a telecommunications system. In this document, the terms “access node” and “network element” may be used interchangeably, but it is understood that an access node may comprise a plurality of hardware and software.
In 3GPP LTE, a cell may refer to a combination of downlink and/or uplink resources. In general, multiple cells may originate from the same access node (e.g., eNB in LTE) and occupy overlapping geographical areas. When there is no danger of confusion, a cell may refer to the distinctive geographical area of reception and transmission coverage provided by an access node. Some cells may have significantly larger coverage area than others and may be referred to herein as macro-cells. Some cells may have significantly smaller coverage area than the macro-cells and may be referred to herein as small cells. Small cells may also include micro-cells, pico-cells, and femto-cells. In some embodiments, small cells may operate within the area covered by a macro-cell.
A radio link may be established between an access node and a UE. The radio link may comprise an uplink signal with communication from the UE to the access node, and a downlink signal with communication from the access node to the UE. The UE may monitor the downlink signal in order to detect a downlink radio link quality in a cell.